If you are going to stay with a 1.6 crop factor then buy a Canon 17-55mm f2.8 IS USM lens and a canon 70-200mm f2.8 L IS USM lens. this combo will bring you close to or a little over 3 grand. If you plan on upgrading to APS-H or FF then get the canon 24-70 f2.8 L USM lens instead of the 17-55mm. This Two lens combo will cover everything you will need even for football and soccer. Use the remaining 1300 dollars from the price of the 300 f2.8 to buy a good image software like lightroom or aperture, Noise Ninja for noise reduction and genuine fractals to create any size enlargement you want. You might even have enough left over to get a nice 50mm f1.4 lens to boot. And IMHO you will never regret spending more money on canon lenses vs. less expensive 3rd party (caveat, I love my sigma 50mm f1.4). Good Luck